Why haven't we seen more microwave weaponry?

Factual Questions
1

I had heard that the military was developing a kind of microwave anti-crowd weapon which could be directed at a crowd of people to incapacitate/scatter them. The idea would be to direct non-lethal amounts of microwaves at people, which would cause a burning sensation on the skin.

With the massacres that have gone on in Iraq regarding military units firing on crowds, it made me think about how beneficial a device like this could be. Attack helicopters could use it on suspicious groups of people, the upshot being that if those people turn out to be ordinary citezens, there’s no permanent damage, as opposed to mistaking them for enemies and shooting them, generating a PR nightmare for the military.

2

What it is from: Howstuffworks.com

"The active-denial system weapon is designed to transmit a narrow beam of electromagnetic energy to heat the skin without causing any permanent damage. The beam is sent out at the speed of light by a transmitter measuring 10 by 10 feet (3 by 3 meters). An intense burning sensation continues until the transmitter is turned off or the targeted individual moves outside of the beam’s range. The exact size and range of the beam is classified, but it is designed for long-range use.

Officials report that the weapon penetrates the skin less than 0.016 inches (0.04 cm), not far enough to damage organs. Long-term exposure to light, such as in sun-tanning, is said to be more harmful than the pain beam. Some human rights activists have voiced concerns about possible damage to eyes, but military officials contend that targeted people would likely close their eyes before damage is done."

and

“According to an Associated Press story, the active-denial technology has been tested on 72 people at Brooks Air Force Base since 1994. Humans have been exposed to the beam more than 6,500 times for an average of less than 10 seconds, with no serious injuries resulting.”

When it will be used from:USAF: Active Denial Technology Fact Sheet

“Their 2002 review of the program concluded there is low probability of serious injury from exposure to the ADS beam. Additionally, the panel concludes that the probability of thermal eye injury is low and the probability of long-term health effects such as cancer is extremely low.”

and

"Under the Advanced Concept Technology Demonstration, the Air Force Research Laboratory will produce a Humvee-mounted prototype and provide it to operational forces from all the services in late 2004. The services will first develop concepts for employing the system and then evaluate its utility in representative military environments and scenarios. Depending on the results of this evaluation, which is projected to be completed at the end of 2005, a decision will be made to produce and operationally deploy the system. Since this is the first time this leading edge technology will be evaluated for military utility, it is possible that some of the services will find they need considerably different system configurations of the ADS which would be tailored for specific missions and operating environments, such as on-board a ship or on an aircraft. Planning for an airborne system prototype has already begun under a separate effort.

The employment of Active Denial Technology has successfully undergone a preliminary weapons legal review. A interim, comprehensive legal review, including treaty compliance, is in process and is projected to be completed this year."

3

Not so much a factual answer as a WAG: Crowd control weapons based on “radiation” of any kind would be a PR nightmare -

“They’re cooking the children!!”

“They’re causing cancer!!”

“Tinfoil hats are no match!!”

Well, maybe not that last one, but still - I don’t see that new microwave-based weapons would be a big PR boost for the military.

4

Well, I dunno, but I thought maybe zapping people with a microwave ray which doesn’t cause permanent damage wouldn’t be as ‘horrific’ as zapping people with, say, 30mm rounds.